The Internet and other networks commonly include many types of media items that may be rendered (i.e., played, displayed or consumed) by users in a variety of ways. For example, many social networking, blogs and other personalized sites render media items such as documents, audio, video, and imagery. Typically, media items that are included on Internet web pages and other network sites reside at particular network locations accessible only through hard-coded static references or network locations.
Increasingly, media providers, particularly those providing time-sensitive media items, wish to make media items available for a limited period of time or vary the collection (i.e., set) of media items that may be rendered by a user. For example, an online repository that accepts uploads of media items may provide static HTML links for a limited duration to media that may be embedded within a user's web page. When the online repository enforces the limited duration, the online repository often deletes or disables the media, thus producing a damaging effect in the user's web page embedding the static HTML link. As another example, a rights holder may release media items for use in a social networking site (e.g., Yahoo! 360 or MySpace) such that the media items are varied on a periodic (e.g., daily) basis. If a series of media items (e.g., short video clips from an upcoming movie) are designed to build toward an event (e.g., a movie release date), the rights holder may wish to vary the media items accessible from the same page that is repeatedly viewed by users. In such a case, if media items are statically referenced, the rights holder must manually update the page in conformance with their event schedule. As yet another example, an advertiser may wish to vary and/or track interaction with media items (e.g., advertisements) rendered on a web page. Particularly, for example, where media items are rendered using a static reference on a web page, the advertiser may be unable to determine when or how often the media item is rendered on a web page. As illustrated by these examples, systems and methods are needed for rendering a collection of media items that may change over a time period or change in some other way.